Abstract
The medical application of infrared thermography makes use of the skin temperature as an indication of an underlying pathological process. In order to study the relation between the heat production from a source in living tissue and the overlying skin temperature, artificial heat sources were implanted subcutaneously in human volunteers. The experimental results show that a detectable surface temperature increase over the heat sources presupposes high power output or superficial implantation. The effect of forced convective heat loss from the skin surface and lowered ambient temperature was studied. Forced convection markedly decreased the temperature contrast. An implicit conclusion from experimental and theoretical work is that a localized 'hot spot' can only exceptionally be attributed to metabolic heat production conducted to the skin surface from a buried pathological process.